Validation of Basophil CD164 Upregulation for Pollen Allergy Diagnosis

Abstract

The aim of the study was to evaluate the sensitivity and specificity of allergen-induced basophil CD164 upregulation in patients with seasonal allergic rhinitis caused by allergy to grass pollens. This study was performed in 24 patients with allergy to grass pollens, and in 25 healthy controls. The protocol for allergen-induced basophil CD164 upregulation consisted of whole blood samples processing and staining with anti-CCR3/anti-CD164 antibodies added to a buffer at the beginning of stimulation. We observed dose-dependent allergen-induced basophil CD164 upregulation with 100% of specificity in both used allergen concentrations (12 and 1.2 ng/ml). Higher allergen concentration resulted in 100% and lower concentration in only 70.83% sensitivity. We have observed in the patients statistically significant correlations between anti-IgE stimulation and both allergen concentrations (for 12 ng/ml, r = 0.71, p < 0.0001; and for 1.2 ng/ml, r = 0.64, p < 0.001). We conclude that assessment of allergen-induced basophil CD164 upregulation is a very useful method for in vitro determination of allergy to grass pollens. This method seems to be a very promising tool in laboratory testing of allergies to other allergens.

CD164 and other recently discovered activation markers as promising tools for allergy diagnosis: what’s new?

“…Some authors have suggested that its expression in human basophil should follow the typical behaviour of CD203c. Wolanczyk-Medrala and colleagues reported that CD164 presumably reaches its maximal expression within 20 min from the stimulation, a value that is quite similar to previously reported data for CD203c, although CD164 expression has a smooth time course and CD203c reaches more than 60% expression within the first 5 min [10,13,16]. However, while CD203c appears to be solely expressed on basophils among blood cells, CD164 is expressed in other haematopoietic cells [17].…”

“…Moreover, there are few data on asthma risk factors and phenotypes in patients with seasonal allergic rhinitis, as severe rhinitis (together with poly-sensitization in adults) appears to be the dominant asthma phenotype [3]. In this context, classical skin test in allergic rhinitis is still considered a good diagnostic tool [4,5], but in recent years, the evaluation of allergen-induced basophil activation by following surface marker up-regulation has become the hallmark of several reports about pollen allergy diagnosis [6][7][8][9][10].…”

“…Actually, a correct allergy diagnosis requires laboratory support to prevent potentially adverse systemic reactions during traditional clinical testing. The recent introduction of CD164 is a clear example of this trend [10][11][12][13]. CD164 is a sialomucin present in CD34-expressing cells, which is involved in cellular adhesion [14,15] and plays an important role in haematopoiesis by allowing human CD34?…”

“…CD164 is a sialomucin present in CD34-expressing cells, which is involved in cellular adhesion [14,15] and plays an important role in haematopoiesis by allowing human CD34? cells to adhere to stroma [10]. In basophils, this molecule is a member of the ''fast responders'', having been functionally associated with CD13 and CD203c [13] but, as for the ectoenzyme CD203c, the role of CD164 in allergy is currently unknown.…”

“…A role for CD164 reactivity is played by the differential epitopes expressed on basophils, as class III antibodies (67D2 and N6B6) show better performance in differentiating resting from activated basophils; so, a critical point for this marker when compared with CD203c might be the different expression on resting and activated basophils of different epitopes recognized by the antibody, an issue that might render more complex the analytical performance and product specificity of the latter [13]. When used as the specific activation marker in basophils gated with anti-CCR3 antibodies [18], CD164 shows a very high sensitivity and specificity at the highest allergen concentration used and a very good correlation with 0.2 lg/ml anti-IgE stimulation [10]. This high sensitivity is encouraging if one considers that it occurs without the use of IL-3 [11].…”